Platform mergers and antitrust[Ex-post assessment of merger control decisions in digital markets]

Should internet era merger policy differ from industrial era merger policy? Platform ecosystems rely on economies of scale, data-driven economies of scope, high-quality algorithmic systems, and strong network effects that frequently promote winner-take-most markets. Their market dominance has generated competition concerns that appear difficult to assess with traditional merger policy tools. This paper examines the acquisition strategies of the five major U.S. platforms—Google, Amazon, Facebook, Apple, and Microsoft—since their inception. We discuss the main merger and acquisition theories of harm and how these operate differently than in the past. To address merger and acquisition concerns of multi-sided platforms, we develop four proposals that incorporate (i) a new ex ante regulatory framework, (ii) an update of the conditions under which the notification of mergers should be compulsory and the burden of proof should be reversed, (iii) differential regulatory priorities in investigating horizontal versus vertical acquisitions, and (iv) an update of competition enforcement tools to increase visibility into market data and trends.